The present invention relates to a dielectric waveguide, and particularly relates to a structure of an input/output section for a signal to/from the dielectric waveguide, a mounting structure for the dielectric waveguide onto a board, a dielectric waveguide filter and a Massive MIMO system.
As an input/output structure for enabling a dielectric waveguide filter or the like formed by coupling a plurality of dielectric waveguide resonators to be mounted directly onto a printed circuit board, an input/output structure of a dielectric waveguide in which input/output electrodes are formed on bottom faces and side walls of dielectric waveguide resonators that perform inputting/outputting has been used, as disclosed, for example, in Japanese Patent Unexamined Publication No. 2002-135003 and 2003-110307 bulletins.
FIG. 17 is a bottom perspective view showing an example of a dielectric waveguide filter utilizing the input/output structure of the dielectric waveguide described in the Japanese Patent Unexamined Publication No. 2002-135003 and 2003-110307 bulletins.
The dielectric waveguide filter 100 consists of a plurality of dielectric waveguide resonators 102 of which resonance mode is TE mode. The dielectric waveguide resonators 102 are coupled through slits 103. Bottom faces 102b of the dielectric waveguide resonators 102 are each provided with belt-shaped input/output electrodes 105 respectively extending from the middle of two sides that are opposite each other toward the directions of the opposite sides. Environs along both side portions and an end portion of each of the input/output electrodes 105 are provided with conductor-unformed sections 106, 107. The rest of the portions are covered with a conductive film.